Larbi Belhoucine’s research while affiliated with Eawag: Das Wasserforschungs-Institut des ETH-Bereichs and other places

An explicit algebraic Reynolds stress model (EARSM) is proposed for the simulation of the incompressible three-dimensional Reynolds averaged Navier–Stokes (RANS) equations. The spatial discretization of the RANS equations is performed by a finite volume method with nonstaggered variable arrangement.The EARSM model which accounts for rotational effects is used to compute the turbulent flows in rotating straight square duct. The Reynolds number of 48,000 is based on the bulk velocity and the hydraulic diameter of the duct and is kept constant in the range of the rotational numbers. The second order closure (EARSM) yields an asymmetric mean velocity profile as well as turbulence properties. Effects of rotation near the cyclonic (suction side) and anticyclonic (pressure side) walls are well observed. Direct numerical simulation and large eddy simulation data are available for this case. The comparison of EARSM results with these accurate simulations shows a very good agreement.

This paper aims at extending the Pressure Substitution Method (PSM) to the three-dimensional turbulent incompressible flows in complex geometries, using a curvilinear coordinate system. The use of non-staggered grid to store different variables requires the use of special interpolation (Rhie and Chow, 1983) to link the pressure to the velocity fields. In order to complete the transport equations, the k-ε turbulence model is used. To validate the present algorithm, it has been applied to predict the three-dimensional turbulent flow in several tests, such as the rotating duct and curved turbulent duct flows. The latter has revealed the efficiency of the code to. collect, with a sufficient precision, the secondary flows which occur under the effect of the centrifugal force. The predictions are compared with available measurements and computational data.